Geographic variation in host selection in the spider wasps Entypus unifasciatus (Say) and Tachypompilus ferrugineus (Say) (Hymenoptera: Pompilidae)

Abstract

Geography and host spider family are strongly linked in the spider wasps (Hymenoptera: Pompilidae) Entypus unifasciatus (Say) and Tachypompilus ferrugineus (Say) (rusty spider wasp) when 2031 host spider locality records from the years 1918–2020 are mapped. Entypus unifasciatus lycosid host records are plentiful from 43–44° N in the U.S. to northern Mexico. Tachypompilus ferrugineus lycosid host records are numerous from southern Ontario and New England to Mexico east of the Rocky Mountains. Most E. unifasciatus and T. ferrugineus pisaurid host records are from the SE U.S. Trechaleid host records for E. unifasciatus and T. ferrugineus are predominant in southern Mexico and Central America, while ctenid host records for these species are prevalent in northern South America. All E. unifasciatus sparassid host records are from extreme SW U.S. and Mexico, whereas T. ferrugineus sparassid host records are scattered from Texas, Florida and Puerto Rico to Panama. Lycosidae are the predominant host spider family in the Americas for E. unifasciatus (80.3%) and T. ferrugineus (67.4%) followed by Pisauridae (5.4%, 21.7%), Trechaleidae (4.8%, 6.8%), Ctenidae (4.6%, 1.8%), and Sparassidae (4.3%, 1.5%). Lycosidae and Pisauridae are overrepresented in this study as the vast majority of host records (87.8%) are from the U.S. and Ontario, Canada where such species are abundant. Trechaleidae and Ctenidae are grossly underrepresented as host records from Mexico, Central America and South America are scarce (12.2%). Zoropsidae/Miturgidae and Zoropsidae/Agelenidae are atypical host families for E. unifasciatus (0.3%, 0.3%) and T. ferrugineus (0.4%, 0.4%), respectively. Rabidosa rabida (Walckenaer) (Lycosidae) (rabid wolf spider) is the predominant host spider species for both E. unifasciatus (56.8%) and T. ferrugineus (58.3%).